This application claims the priority of Korean Patent Application No. 2002-67397, filed on Nov. 1, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a combined TV (television) and FM (frequency modulation) radio receiver and a method to receive TV and FM radio signals, and more particularly, to a combined TV and FM radio receiver capable of, and a method for, selectively receiving TV and FM radio signals via a single tuner using a digital IF (intermediate frequency) stage.
2. Description of the Related Art
A TV receiver for receiving broadcasting signals, e.g., TV signals and FM radio signals, transmitted in different frequency bands typically includes a plurality of tuners in correspondence with the respective frequency bands and a plurality of detection circuits for detecting signals selected via the respective tuners.
FIG. 1 is a block diagram of a conventional combined TV and FM radio receiver. Referring to FIG. 1, a TV tuner 110 converts TV signals received via an antenna into IF signals. A video band filter 112 extracts video band signals from the IF signals output from the TV tuner 110. A video IF converter 116 coverts the video signals extracted by the video band filter 112 into video baseband signals. A video demodulator 120 extracts composite video baseband signals (CVBS) from the baseband signals output from the video IF converter 116. A video processor 122 converts the composite video baseband signals extracted by the video demodulator 120 into red (R), green (G), and blue (B) color signals and outputs them via a CRT (cathode ray tube) 124.
An audio band filter 114 extracts audio band signals from the IF signals output from the TV tuner 110. An audio IF converter 118 converts the audio signals extracted by the audio band filter 114 into audio baseband signals.
Meanwhile, a radio tuner 132 receives FM radio signals via another antenna. An amplifier 134 amplifies the FM radio signals received via the radio tuner 132. A radio IF converter 136 converts the FM radio signals amplified via the amplifier 134 into IF band signals. An audio demodulator 142 extracts and demodulates audio signals from the audio baseband signals extracted by the audio IF converter 118 and the IF band signals extracted by the IF converter 136. A sound processor 144 amplifies the audio signals demodulated by the audio demodulator 142 and outputs them via a speaker 146.
As described above, the conventional combined TV and FM radio receiver has required not only a TV tuner but also a separate radio tuner and other radio signal processing elements, such as an amplifier, a radio IF converter, etc. Accordingly, the structure of the conventional receiver is complex and the production cost thereof is high.